package types import ( "context" "fmt" cmn "github.com/tendermint/tendermint/libs/common" "github.com/tendermint/tendermint/libs/log" tmpubsub "github.com/tendermint/tendermint/libs/pubsub" ) const defaultCapacity = 0 type EventBusSubscriber interface { Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, outCapacity ...int) (Subscription, error) Unsubscribe(ctx context.Context, subscriber string, query tmpubsub.Query) error UnsubscribeAll(ctx context.Context, subscriber string) error NumClients() int NumClientSubscriptions(clientID string) int } type Subscription interface { Out() <-chan tmpubsub.Message Cancelled() <-chan struct{} Err() error } // EventBus is a common bus for all events going through the system. All calls // are proxied to underlying pubsub server. All events must be published using // EventBus to ensure correct data types. type EventBus struct { cmn.BaseService pubsub *tmpubsub.Server } // NewEventBus returns a new event bus. func NewEventBus() *EventBus { return NewEventBusWithBufferCapacity(defaultCapacity) } // NewEventBusWithBufferCapacity returns a new event bus with the given buffer capacity. func NewEventBusWithBufferCapacity(cap int) *EventBus { // capacity could be exposed later if needed pubsub := tmpubsub.NewServer(tmpubsub.BufferCapacity(cap)) b := &EventBus{pubsub: pubsub} b.BaseService = *cmn.NewBaseService(nil, "EventBus", b) return b } func (b *EventBus) SetLogger(l log.Logger) { b.BaseService.SetLogger(l) b.pubsub.SetLogger(l.With("module", "pubsub")) } func (b *EventBus) OnStart() error { return b.pubsub.Start() } func (b *EventBus) OnStop() { b.pubsub.Stop() } func (b *EventBus) NumClients() int { return b.pubsub.NumClients() } func (b *EventBus) NumClientSubscriptions(clientID string) int { return b.pubsub.NumClientSubscriptions(clientID) } func (b *EventBus) Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, outCapacity ...int) (Subscription, error) { return b.pubsub.Subscribe(ctx, subscriber, query, outCapacity...) } // This method can be used for a local consensus explorer and synchronous // testing. Do not use for for public facing / untrusted subscriptions! func (b *EventBus) SubscribeUnbuffered(ctx context.Context, subscriber string, query tmpubsub.Query) (Subscription, error) { return b.pubsub.SubscribeUnbuffered(ctx, subscriber, query) } func (b *EventBus) Unsubscribe(ctx context.Context, subscriber string, query tmpubsub.Query) error { return b.pubsub.Unsubscribe(ctx, subscriber, query) } func (b *EventBus) UnsubscribeAll(ctx context.Context, subscriber string) error { return b.pubsub.UnsubscribeAll(ctx, subscriber) } func (b *EventBus) Publish(eventType string, eventData TMEventData) error { // no explicit deadline for publishing events ctx := context.Background() b.pubsub.PublishWithTags(ctx, eventData, map[string]string{EventTypeKey: eventType}) return nil } func (b *EventBus) validateAndStringifyTags(tags []cmn.KVPair, logger log.Logger) map[string]string { result := make(map[string]string) for _, tag := range tags { // basic validation if len(tag.Key) == 0 { logger.Debug("Got tag with an empty key (skipping)", "tag", tag) continue } result[string(tag.Key)] = string(tag.Value) } return result } func (b *EventBus) PublishEventNewBlock(data EventDataNewBlock) error { // no explicit deadline for publishing events ctx := context.Background() resultTags := append(data.ResultBeginBlock.Tags, data.ResultEndBlock.Tags...) tags := b.validateAndStringifyTags(resultTags, b.Logger.With("block", data.Block.StringShort())) // add predefined tags logIfTagExists(EventTypeKey, tags, b.Logger) tags[EventTypeKey] = EventNewBlock b.pubsub.PublishWithTags(ctx, data, tags) return nil } func (b *EventBus) PublishEventNewBlockHeader(data EventDataNewBlockHeader) error { // no explicit deadline for publishing events ctx := context.Background() resultTags := append(data.ResultBeginBlock.Tags, data.ResultEndBlock.Tags...) // TODO: Create StringShort method for Header and use it in logger. tags := b.validateAndStringifyTags(resultTags, b.Logger.With("header", data.Header)) // add predefined tags logIfTagExists(EventTypeKey, tags, b.Logger) tags[EventTypeKey] = EventNewBlockHeader b.pubsub.PublishWithTags(ctx, data, tags) return nil } func (b *EventBus) PublishEventVote(data EventDataVote) error { return b.Publish(EventVote, data) } func (b *EventBus) PublishEventValidBlock(data EventDataRoundState) error { return b.Publish(EventValidBlock, data) } // PublishEventTx publishes tx event with tags from Result. Note it will add // predefined tags (EventTypeKey, TxHashKey). Existing tags with the same names // will be overwritten. func (b *EventBus) PublishEventTx(data EventDataTx) error { // no explicit deadline for publishing events ctx := context.Background() tags := b.validateAndStringifyTags(data.Result.Tags, b.Logger.With("tx", data.Tx)) // add predefined tags logIfTagExists(EventTypeKey, tags, b.Logger) tags[EventTypeKey] = EventTx logIfTagExists(TxHashKey, tags, b.Logger) tags[TxHashKey] = fmt.Sprintf("%X", data.Tx.Hash()) logIfTagExists(TxHeightKey, tags, b.Logger) tags[TxHeightKey] = fmt.Sprintf("%d", data.Height) b.pubsub.PublishWithTags(ctx, data, tags) return nil } func (b *EventBus) PublishEventNewRoundStep(data EventDataRoundState) error { return b.Publish(EventNewRoundStep, data) } func (b *EventBus) PublishEventTimeoutPropose(data EventDataRoundState) error { return b.Publish(EventTimeoutPropose, data) } func (b *EventBus) PublishEventTimeoutWait(data EventDataRoundState) error { return b.Publish(EventTimeoutWait, data) } func (b *EventBus) PublishEventNewRound(data EventDataNewRound) error { return b.Publish(EventNewRound, data) } func (b *EventBus) PublishEventCompleteProposal(data EventDataCompleteProposal) error { return b.Publish(EventCompleteProposal, data) } func (b *EventBus) PublishEventPolka(data EventDataRoundState) error { return b.Publish(EventPolka, data) } func (b *EventBus) PublishEventUnlock(data EventDataRoundState) error { return b.Publish(EventUnlock, data) } func (b *EventBus) PublishEventRelock(data EventDataRoundState) error { return b.Publish(EventRelock, data) } func (b *EventBus) PublishEventLock(data EventDataRoundState) error { return b.Publish(EventLock, data) } func (b *EventBus) PublishEventValidatorSetUpdates(data EventDataValidatorSetUpdates) error { return b.Publish(EventValidatorSetUpdates, data) } func logIfTagExists(tag string, tags map[string]string, logger log.Logger) { if value, ok := tags[tag]; ok { logger.Error("Found predefined tag (value will be overwritten)", "tag", tag, "value", value) } } //----------------------------------------------------------------------------- type NopEventBus struct{} func (NopEventBus) Subscribe(ctx context.Context, subscriber string, query tmpubsub.Query, out chan<- interface{}) error { return nil } func (NopEventBus) Unsubscribe(ctx context.Context, subscriber string, query tmpubsub.Query) error { return nil } func (NopEventBus) UnsubscribeAll(ctx context.Context, subscriber string) error { return nil } func (NopEventBus) PublishEventNewBlock(data EventDataNewBlock) error { return nil } func (NopEventBus) PublishEventNewBlockHeader(data EventDataNewBlockHeader) error { return nil } func (NopEventBus) PublishEventVote(data EventDataVote) error { return nil } func (NopEventBus) PublishEventTx(data EventDataTx) error { return nil } func (NopEventBus) PublishEventNewRoundStep(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventTimeoutPropose(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventTimeoutWait(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventNewRound(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventCompleteProposal(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventPolka(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventUnlock(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventRelock(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventLock(data EventDataRoundState) error { return nil } func (NopEventBus) PublishEventValidatorSetUpdates(data EventDataValidatorSetUpdates) error { return nil }